Biology Ch. 1

Front 1

Lipid

Back 1

-Any biological molecule that has low solubility in water and high solubility in organic solvents.
-hydrophobic, make barriers separating aqueous environments.

Front 2

Fatty acids

Back 2

-Long chains of carbons truncated at one end by carboxylic acid.
-usually an even number of carbons
-saturated and unsaturated fatty acids
-may serve as local hormones

Front 3

Triaclyglycerols (Triglycerides)

Back 3

-make up fats, oils
-constructed from a 3 carbon backbone called glycerol
-the glycerol is attached to three fatty acids
-store metabolic energy, provide thermal insulation and padding

Front 4

Phospholipids

Back 4

-built from a glycerol backbone but a polar phosphate group replaces one of the fatty acids
-amphipathic, major component of membranes

Front 5

Steroids

Back 5

-four ring structures
-include hormones, vitamin D, cholesterol.
-regulate metabolic activities

Front 6

Eicsanoids

Back 6

-released from cell membranes as local hormones that regulate blood pressure, body temperature, smooth muscle contraction.
-include prostaglandin, thromboxanes, leukotrienes.

Front 7

lipoproteins

Back 7

-contain a lipid core surrounded by phospholipids and apoproteins.
-Able dissolve lipids in its hydrophobic core than move freely through the aqueous solution

Front 8

Proteins

Back 8

-built from amino acids linked together by peptide bonds
-polypeptides

Front 9

amino acid

Back 9

-link together by peptide bonds to form proteins
-amino acids in solution will always carry one or more charges depending on the pH of the solution

Front 10

primary structure

Back 10

the number and sequence of amino acids in a polypeptide

Front 11

B-pleated sheet

Back 11

-The connecting structure of two DNA strands of the sheet can lie in the same direction or in the opposite direction.
-a form of secondary structure

Front 12

Secondary structure

Back 12

-contribute to the conformation of the protein
-alpha helix or beta pleated sheet

Front 13

tertiary structure

Back 13

the 3 dimensional shape formed when the peptide chain curls and folds.

Front 14

The 5 forces that create tertiary structure

Back 14

1. covalent disulfide bonds between two cysteine amino acids on different parts of a chain
2. electrostatic (ionic) interactions mostly between acidic and basic side chains
3. hydrogen bonds
4. van der Waals forces
5. hydrophobic side chains pushed away from water (toward the center of the protein)

Front 15

Quaternary structure

Back 15

-When two or more polypeptide chains bond together
-same forces at work in the tertiary structure can also act to form the quaternary structure

Front 16

Carbohydrates

Back 16

-made from carbon and water
-also known as sugars and saccharides
-empirical formula C(H2O)

Front 17

Glucose

Back 17

-The most commonly occurring carbohydrate.
-alpha glucose: methoxy and hydroxyl on anomeric carbon on opposite sides
-beta glucose: methoxy and hydroxyl on anomeric carbon are on the same side.
-animals eat alpha linkages, only bacteria break down beta linkages

Front 18

Glycogen

Back 18

-If a cell has sufficient ATP, glucose is polymerized to the polysaccharide glycogen or converted to fat.
-found in animal cells, formed when glucose has alpha linkages

Front 19

Starch

Back 19

-alpha linkages between glucose molecules, formed by plants

Front 20

Cellulose

Back 20

-a storage form of glucose, beta linkages

Front 21

Nucleotides

Back 21

-Nucleotides form polymers to create the nucleic acids RNA and DNA
-made of:
1. a five carbon sugar
2. a nitrogenous base
3. a phosphate group

Front 22

phosphodiester bonds

Back 22

-bond between the phosphate group of one nucleotide and the 3rd carbon of the pentose of the other nucleotide forming long strands (nucleic acids)

Front 23

Minerals

Back 23

-dissolved inorganic ions inside and outside the cell.
-by creating an electrochemical gradient across membranes, assist in the transport of substances entering and exiting the cell.

Front 24

Enzyme

Back 24

-the function of an enzyme is to act as a catalyst, lowering the energy of activation for a biological reaction and increasing the rate of reaction
-Enzymes do not alter the equilibrium of a reaction

Front 25

Substrate

Back 25

The reactant or reactants on which an enzyme works

Front 26

Active site

Back 26

-The position on the enzyme to where the substrate usually binds, usually with numerous noncovalent bonds.

Front 27

Lock and key theory of enzymes

Back 27

-The active site of the enzyme has a specific shape like a lock that only fits a specific substrate, the key.

Front 28

Induced fit theory of enzymes

Back 28

-The shape of both the enzyme and the substrate are altered upon binding.
-the alteration increases specificity and helps the reaction proceed.

Front 29

Saturation kinetics

Back 29

-As the concentration of substrate relative to enzyme increases, the rate of reaction also increases, but to a lesser and lesser degree until a maximum rate (Vmax) has been achieved.

Front 30

Cofactor

Back 30

-in order to reach their optimal activity, most enzymes require a non-protein component called a cofactor.
-can be either coenzymes or metal ions.

Front 31

Coenzymes

Back 31

-A type of cofactor which is an organic molecule, as apposed to a metal ion that functions as a cofactor. Helps enzymes to reach their optimal activity.
-often vitamins or their derivatives

Front 32

Irreversible inhibitors

Back 32

Agents which bind covalently to enzymes at the active site and disrupt their function

Front 33

Competitive inhibitors

Back 33

-Compete with the substrate by binding reversibly with noncovalent bonds to the active site
-If substrate is added, Vmax can be achieved again.

Front 34

Noncompetitive Inhibitors

Back 34

-Bind noncovalently to an enzyme at a spot other than the active site and change the conformation of the enzyme.
-Do NOT prevent the substrate from binding.
-Do lower Vmax.

Front 35

Zymogen

Back 35

-Also known as a proenzyme
-Most enzymes are released into the environment in an inactive form called a zymogen.
-When specific peptide bonds on the zymogens are cleaved, they become irreversibly activated. (Proteolytic cleavage).

Front 36

Allosteric Interactions

Back 36

-The modification of the enzyme configuration resulting from the binding of an activator or an inhibitor at a specific binding site on the enzyme.

Front 37

Negative Feedback

Back 37

-If an enzyme product downstream in a reaction series comes back and inhibits the enzyme activity in an earlier reaction, the phenomenon is called negative feedback or feedback inhibition.
-provides a shutdown mechanism when a series has produced a sufficient amount of product.

Front 38

Positive Feedback

Back 38

-Occurs where a product returns to activate the enzyme.

Front 39

Positive cooperativity

Back 39

When a substrate changes the shape of an enzyme allowing other substrates to bind more easily.

Front 40

Negative cooperativity

Back 40

When a substrate changes the shape of an enzyme making it more difficult for substrates to bind to the active site.

Front 41

Lyase

Back 41

An enzyme that catalyzes addition of one substrate to a double bond of a second substrate.

Front 42

Ligase

Back 42

Also governs and addition reaction like a lyase, but requires energy from ATP or some other nucleotide

Front 43

Kinase

Back 43

An enzyme which phosphorylates something

Front 44

Phosphatase

Back 44

An enzyme which dephosphorylates something

Front 45

Metabolism

Back 45

-All cellular chemical reactions
-consists of anabolism and catabolism
-

Front 46

The 3 basic stages of metabolism

Back 46

1. Macromolecules (lipids, polysaccharides, proteins) are broken down into their constituent parts
2. Constituents are oxidized into Acetyl CoA, pyruvate, or other metabolites forming some ATP and reduced coenzyme (NADH or FADH2) in a process that does not directly utilize oxygen
3. If oxygen is available and the cell is capable of using oxygen, these metabolites go into the citric acid cycle and oxidative phosphorylation to form large amounts of energy.

Front 47

Respiration

Back 47

-The energy acquiring stages of metabolism. (second and third stages)
-Aerobic and anaerobic respiration.

Front 48

Anaerobic respiration

Back 48

-when oxygen is not required for respiration.

Front 49

Glycolysis

Back 49

-The first stage of anaerobic and aerobic respiration
-A series of reactions that brakes a 6-carbon glucose molecule into a 3-carbon molecule called pyruvate
-2 ATP, PO4, H2O, 2NADH are formed
-Occurs in the cytosol of living cells

Front 50

Pyruvate

Back 50

-A 3 carbon molecule that is produced via glycolysis 6-C glucose.
-The conjugate base of pyruvic acid.
-Produced at the end of glycolysis.

Front 51

Pyruvic acid

Back 51

-The conjugate acid of pyruvate, produced in glycolysis.

Front 52

Cytosol

Back 52

-The fluid portion of living cells.
-Location of glycolysis.

Front 53

Substrate level phosphorylation

Back 53

The formation of ATP from ADP and inorganic phosphate using the energy released from the decay of high energy phosphorylated compounds as opposed to energy from diffusion.

Front 54

Fermentation

Back 54

-Anaerobic respiration.
-Includes the process of glycolysis, the reduction of pyruvate to ethanol or lactic acid, and the oxidation of NADH back to the NAD+.
-NAD+ is restored for its role in glycolysis as a coenzyme, and the lactic acid or ethanol is expelled from the cell along with carbon dioxide as a waste product.
-produces 2 net ATP

Front 55

Aerobic Respiration

Back 55

-Respiration that requires oxygen
-if a cell is capable of aerobic respiration the products of glycolysis will move into the matrix of the mitochondrion.
-produces 36 net ATP

Front 56

Acetyl CoA

Back 56

A coenzyme which transfers two carbons (two carbons from pyruvate) to the 4-carbon oxaloacetic acid to begin the Kreb's cycle

Front 57

Krebs cycle

Back 57

-Each turn of the kreb's cycle produces 1 ATP, 3 NADH, 1 FADH2.
-Looses two carbons as CO2, 1 FADH2.
-Occurs during aerobic respiration
-Takes place in the mitochondrial matrix
-one glucose molecule is used up in each turn of the Kreb's cycle
-fatty acids can be catabolized for energy via the kreb's cycle.

Front 58

Electron transport chain (ETC)

Back 58

-A series of proteins including cytochromes with heme in the inner membrane of the mitochondrion.
-The first protein complex in the series oxidizes NADH by accepting its high energy electrons.
-Electrons are then passed down the protein series and ultimately accepted by oxygen to form water.
-As the electrons are passed along, protons are pumped into the intermembrane space for each NADH
-This establishes a proton gradient which propels protons through ATP synthase to manufacture 3 ATPs for each NADH.

Front 59

ATP synthase

Back 59

an enzyme that manufactures ATP when the proton motive force established by the ETC propels protons through the enzyme.

Front 60

Oxidative Phosphorylation

Back 60

-a metabolic pathway that uses energy released by the oxidation of nutrients to produce ATP.
-Occurs via the ETC.